Disconnecting switch assembly

ABSTRACT

The invention relates to a disconnecting switch assembly for disconnecting air-insulated electrical lines, which have one or more phases, with at least one grounded housing that is filled with protective gas, with open air ducts, which are attached to the housing(s) in a gastight manner and which each have an open-air connection for connecting the lines, and with gas-insulated disconnecting switches, which are placed inside the open-air ducts. At least three open air ducts are provided for each phase whose open-air connections can be electrically connected to one another by means of the disconnecting switch over current path piece mounted inside the housing.

CLAIM FOR PRIORITY

This application is a national stage of PCT/DE2004/000966 which waspublished on May 3, 2004 and which claims the benefit of priority toGerman Application No. 103 25 683.0 filed Jun. 2, 2003.

TECHNICAL FIELD OF THE INVENTION

The invention relates to a switch disconnector arrangement fordisconnection of air-insulated electrical lines.

BACKGROUND OF THE INVENTION

By way of example, switch disconnector arrangements are known from DE198 39 535 A1. The switch disconnector arrangement disclosed there hasair-insulated switch disconnectors with two pivoting arms, with thepivoting arms being provided with switching contacts at the ends. In acontact position, the switching contacts rest on mating contacts of livelines or busbars. The pivoting arms are disconnected from the matingcontacts by introduction of a pivoting movement, so that the lines areinterrupted. Air-insulated switch disconnector arrangements arespace-consuming, owing to the minimum separations which have to becomplied with in air. Furthermore, the contacts of the switchdisconnectors are subject to weather influences, and these have adisadvantageous influence on them.

Furthermore, separately installed switch disconnectors with inert gasinsulation are known.

U.S. Pat. No. 4,440,996 discloses a gas-insulated switchgearinstallation which has a metallic enclosure, with a Y-shaped crosssection, at ground potential. The enclosure forms connecting stubs forfitting outdoor bushings in a gas-tight manner. A circuit breaker isarranged in the outdoor bushings and has a stationary contact and amoving contact, which is guided such that it can move with respect tothe stationary contact. In order to quench any arc that is struck ondisconnection of the contacts of the circuit breaker, the arc is blownwith a quenching gas.

U.S. Pat. No. 6,459,562 B2, discloses a switchgear assembly having ametallic enclosure which is at ground potential and is connected tooutdoor bushings in a gas-tight manner. A circuit breaker is providedwithin one of the outdoor bushings while, in contrast, one or two switchdisconnectors is or are arranged in the metallic enclosure.

EP 1 207 601 A2 discloses a switchgear assembly having a metallicenclosure which is installed in an isolated form and to which hollowcylinders, which are manufactured from dielectric material, areattached. Both switch disconnectors and circuit breakers are arranged inthe hollow cylinders. The metallic enclosure is at a high-voltagepotential. The isolated installation of the enclosure is achieved bymeans of a hollow cylinder which is manufactured from dielectricmaterial and is supported on a grounded foundation. Isolating rodsextend through the supporting hollow cylinder and introduce a drivemovement, which is produced by a grounded drive unit, into the metallicenclosure, which is at high-voltage potential.

EP 1 174 968 A1 discloses a high-voltage switchgear assembly which has agas-insulated busbar, a gas-insulated metallic enclosure at groundpotential, and an outdoor bushing, which is connected in a gas-tightmanner to the enclosure, for connection of an air-insulated high-voltagecable. A circuit breaker is provided in the outdoor bushing, in order tointerrupt the current flow. In contrast, at least one switchdisconnector is provided in the gas-insulated enclosure and opens withno current flowing after the current has been interrupted, in order toprovide a sufficiently long isolating gap and thus permanentinterruption of the current flow through the switchgear assembly.

DE 296 20 438 U1 discloses an encapsulating enclosure for agas-insulated switchgear assembly. A switch drive enclosure, which isintended to hold at least one driveshaft, is integrally formed on theencapsulating enclosure.

JP 5453237 A discloses a switchgear assembly which has a metallicenclosure which is at ground potential and in which a circuit breaker isarranged. Connecting stubs, to each of which an outdoor bushing isattached in a gas-tight manner, are integrally formed on the metallicenclosure. Switch disconnectors are provided in the outdoor bushing. Inthis case, the outdoor bushings are formed from a hollow-cylindricalceramic tube and an intermediate enclosure which lengthens the ceramictube. The intermediate enclosure is designed to hold and provide abearing for the switch disconnector drive.

SUMMARY OF THE INVENTION

One object of the invention is to provide a compact switch disconnectorarrangement which can be used to provide a large number of electricalcircuits, in particular for high voltages.

The invention achieves this object by a switch disconnector arrangementfor disconnection of air-insulated electrical lines which have one ormore phases, having at least one grounded enclosure which is filled withinert gas, having outdoor bushings which are attached to the enclosureor enclosures and each have an outdoor connection for connection of thelines, and having gas-insulated switch disconnectors which are arrangedin the outdoor bushings, with at least three outdoor bushings beingprovided for each phase, whose outdoor connections can be electricallyconnected to one another by means of the switch disconnectors via a poleelement which is arranged in one of the enclosures, and with eachoutdoor bushing having a switch disconnector.

The switch disconnector arrangement according to the invention allowsthe switch disconnectors in an outdoor switchgear assembly to becombined to form an assembly which is insulated by inert gas and is thuscompact. The switch disconnectors are no longer installed as individualappliances with individual foundations, but either have a singleenclosure or a separate enclosure for each phase, which can be installedon only one frame with a single foundation. In this case, the switchdisconnector arrangement according to the invention is suitable for alarge number of switching plan applications. Just by way of example, thelink between a double busbar in a three-phase network and a transformerbranch or the connection of two network branches in a so-called Hcircuit may be mentioned. In contrast to already known air-insulatedswitch disconnector arrangements, the switch disconnector arrangementaccording to the invention furthermore has a compact form.

In one preferred further development of the invention, the outdoorbushings which are associated with one phase are arranged in the form ofa fan on one plane. In this case, all the pairs of adjacent outdoorbushings for one phase cover the same angle in their longitudinal extentwith respect to the pole element. The outdoor connections which arearranged at the ends of the outdoor bushings are thus as far apart fromone another as possible. For this reason, the outdoor bushings may bedesigned to have a correspondingly shorter length without any need to beconcerned about voltage flashovers between the outdoor connections. Thisallows the switch disconnector arrangement to have a form which is evenmore compact.

In one further development in this context, the outdoor bushings whichare associated with one phase each run on one plane, with the planes ofthe various phases being aligned parallel to one another.

Insulating posts which are composed of dielectric material areexpediently provided in order to hold the pole element or pieces in theenclosure or enclosures. The insulating posts, which are produced from anon-conductive plastic, a ceramic or, for example, a cast resin, providean insulating holder for the pole element, which is, for example, at ahigh-voltage potential during operation, on the grounded enclosure, withone or multiple pole encapsulation.

A grounding switch is advantageously provided for each phase. Thegrounding switch can simultaneously ground all of the drive-side contactpieces of the switch disconnectors and the pole element for one phaseand, for example, can be arranged in the enclosure, which encapsulatesthree poles or one pole.

The grounding switch is advantageously arranged in the outdoor bushing.This means that there is no need to provide bearings for the groundingswitch in the enclosure.

Each switch disconnector is advantageously held in the outdoor bushingby means of holding means, which are composed of dielectric material.The holding means ensure that the switch disconnector is held in theoutdoor bushing independently of the pole element. This allows theoutdoor bushing to be produced as an independent component together withthe switch disconnector, and to be connected on site to the respectiveenclosure and to the respective pole element, for example via anexpedient plug-in contact. The plug-in contact or other link between theswitch disconnector and the associated pole element provides additionalretention for the switch disconnector, and makes the switch disconnectormore robust.

The holding means are advantageously gas-tight. By way of example, abulkhead bushing may be used as a gas-tight holding means, bounding adisconnector gas area which is formed in the outdoor bushing. In thiscase, a connecting conductor which is electrically connected to theswitch disconnector passes centrally through the bulkhead bushing and isconnected in a gas-tight manner to the bulkhead bushing via expedientsealing means. The disconnector gas area thus forms a disconnector gasarea which is independent of the busbar area of the enclosure and which,for example, can be filled with a different gas and can have a differentpressure applied to it.

In contrast to this, the holding means are gas-permeable, so that acommon gas area which is composed of the disconnector gas area and thebusbar area is formed, and can be checked for leaks by means of a commonsealing test.

The switch disconnector advantageously has contact pieces whose ends arelocated opposite one another, with the switch disconnectoradvantageously having contact pieces which are located opposite oneanother at the ends, in which case the switch disconnector can be movedto a disconnected position by initiation of a linear movement from acontact position which allows current to flow, in which disconnectedposition an electrically isolating gap is provided between the contactpieces.

According to this expedient further development of the invention, thisrefinement of the switch disconnector is very largely matched to ahomogeneous cylindrical conductor which extends in an axial direction,so that it is possible to make use of experience with conventionaloutdoor bushings which do not have any switch disconnectors in theirinterior. This applies not only to their sizes, but also to the materialused.

The switch disconnector expediently has a stationary female contact anda sliding contact, which is firmly supported via a hollow connecting rodon attachment means for the outdoor bushing, with a switching pin, whichis guided by the sliding contact such that it can move, being providedfor making contact with the female contact, and being driven via drivemeans which are arranged in the connecting conductor. The drive meanswhich are arranged in the hollow connecting conductor, for examplecoupling rods, pivoting levers or the like, are encapsulated in thisway, so that voltage peaks on corners and edges of the drive means areavoided, and thus partial discharges, on corners and edges of the drivemeans are avoided, even during a drive movement. Furthermore, the switchdisconnector has two stationary contact pieces which can be held in asimple manner. This therefore avoids a complex moving bearing for acontact piece on the attachment means.

In a further expedient refinement of the invention, at least onedriveshaft is provided in order to introduce a drive movement into theswitch disconnector. In this case, each drive shaft is mounted by meansof an expedient rotating bearing in the attachment means of the outdoorbushing, with expedient sealing means ensuring that the driveshaftpasses through, for example, the outer wall of the attachment means in agas-tight manner.

The driveshaft may, of course, also be mounted in a gas-tight manner inthe enclosure.

The drive movement according to this embodiment of the invention can beintroduced via a rotary movement into the interior of the outdoorbushing, which is gas-insulated during operation.

According to one expedient further development of the invention, anisolating rocker which is composed of a dielectric material is providedin order to introduce a drive movement. The isolating rocker is, forexample, mechanically connected to a coupling rod which forms aswitching pin at its end that is remote from the isolating rocker, whichswitching pin produces the conductive connection between the contactpieces of the switch disconnector when the latter is in the contactposition. The isolating rocker converts a rotary movement as the drivemovement to a linear movement, and introduces a translational movementinto the switch disconnector, in which case the latter is designedappropriately as a push-type switch.

Field control elements are expediently provided in order to avoidpartial discharges in the outdoor bushing.

Furthermore, a display element may be advantageous in order to indicatethe position of the switch disconnector and/or of the grounding switch.

At least one outdoor bushing is advantageously equipped with a currenttransformer. The secondary of the current transformer is connected tothe grounded enclosure and may be in the form of an current adaptor, sothat there is no need to open the common or separate gas area or areasif it becomes necessary to replace the current adaptor.

At least one drive unit, which is supported on the outdoor bushing, isadvantageously provided in order to produce a drive movement. Thisallows the outdoor bushing to be produced as a ready-for-use individualcomponent, independently of the enclosure.

The switch disconnector arrangement according to the inventionexpediently has a voltage transformer. By way of example, the voltagetransformer may be attached to the enclosure.

Further expedient refinements and advantages of the invention are thesubject matter of the following description of exemplary embodiments ofthe invention, with reference to the single FIGURE in the drawing, inwhich:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows one exemplary embodiment of the gas-insulated switchdisconnector arrangement, in the form of a sectioned side view.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows one exemplary embodiment of the gas-insulated switchdisconnector arrangement 1 according to the invention, in the form of asectioned side view. The illustrated switch disconnector arrangement 1has an enclosure 2 which is at ground potential and has three connectingstubs 3 which are each designed to produce a gas-tight connection to oneof the outdoor bushings 4. Only three outdoor bushings 4, which arearranged in the form of a fan on one plane, can be seen in FIG. 1. Thesethree outdoor bushings 4 are associated with one phase of a three-phasenetwork. The remaining outdoor bushings 4 for the other phases areoffset into the plane of the drawing in FIG. 1, and are in each casearranged aligned with one of the illustrated outdoor bushings 4. Intotal, nine outdoor bushings 4 are attached to the enclosure 2.

The outdoor bushing 4 has a hollow-cylindrical isolator 5 with a cavity6 for holding a switch disconnector 7. The switch disconnector 7comprises a stationary female contact 8 and a sliding contact 9, whichis likewise stationary, with the female contact 8 being connected via acontact rod 10 to an outdoor connection 11 for connection of anair-insulated high-voltage line, which is not shown. At the end, theoutdoor connection 11 is arranged on the isolator 5 and has a closurecap 12 which is connected to the isolator 5 in a gas-tight manner byadhesive means, and closes the cavity 6 such that it is gas-tight.

A switching pin 13 is guided in the sliding contact 8 such that it canmove, with the sliding contact 9 being electrically connected to a poleelement 16, which is arranged in the enclosure 2, via a hollowconnecting conductor 14 and via a plug-in contact 15. Insulating postsare provided on the enclosure 2 in order to hold the pole element 16,but are not illustrated in FIG. 1.

The pole element 16 produces an electrical connection between thesliding contacts 9 of one phase. In other words, the contact rods 10,the female contacts 8, the switching pins 13, the sliding contacts 9,the connecting conductors 14, the plug-in contacts 19 and the poleelement 16 produce a conductive connection between all of the outdoorconnections 11 of one phase when all of the switch disconnectors 7 arein a contact position, in which the switching pin 13 has been moved intothe female contact 8.

At the end of the isolator 5 that is remote from the outdoor connection11, each outdoor bushing 4 has attachment means 17 which are producedfrom a metallic material, for example aluminum, and a flange section 18which is adhesively bonded to the isolator 5, and an intermediateenclosure 19. The interiors of the attachment means 17 are likewisetubular, and they have a linear profile in the direction of thelongitudinal extent of the isolator 5. Each intermediate enclosure 19 isfirmly screwed to a connecting stub 3 via a flange connection, withsealing means which cannot be seen ensuring a gas-tight link between theoutdoor bushing 4 and the enclosure 2.

An electrically non-conductive isolating rocker 20, which is arranged inthe intermediate enclosure 19, is provided in order to introduce aswitching movement into the switching pin 13, with side holding caps 21being provided for gas-tight closure of an intermediate cavity 22, whichis bounded by the intermediate enclosure 19. The intermediate cavity 22enlarges the cavity 6.

A gas-tight bulkhead bushing 23 is provided as a holding means or as aholder in order to hold the sliding contact 9 above the connectingconductor 14, and is mounted firmly between the intermediate enclosure19 and the grounded connecting stub 3. In this case, the connecting rod14 passes through the center of the bulkhead bushing 23, with sealingmeans which cannot be seen in FIG. 1 ensuring gas-tight connectionbetween the connecting rod 14 and the bulkhead bushing 23. In this way,the cavity 6 forms a separate, gas-tight disconnector gas area, whichcan be filled with its own quenching or insulating gas, such as sulfurhexafluoride. In the operating state, in which all of the outdoorbushings are installed, the enclosure likewise bounds a closed enclosuregas area, which is likewise filled with a conventional insulating gas.

The bulkhead bushing 23 is produced from a dielectric material, such ascast resin.

The outdoor connection 11 is intended for connection of an air-insulatedhigh-voltage line, which is not illustrated in the FIGURE, while incontrast the enclosure 2 is at ground potential. In order to avoidvoltage peaks resulting from high electrical field strengths on cornersand edges of the attachment means 17, field control elements 24 areprovided, and are electrically connected to the attachment means 17 andto the enclosure 2.

A coupling rod 25 is provided in order to transmit the drive movementfrom the isolating rocker 20 to the switching pin 13, is articulated onthe isolating rocker 20 and is firmly connected to the switching pin 13via a switching pin guide 26 at its end remote from the isolating rocker20. As can be seen, the switching pin 13 and the switching pin guide 26are arranged within the hollow connecting conductor 14, which for thisreason is used as a guide means in addition to providing a purelyelectrical connection. In order to allow movement of the isolatingrocker 20, the connecting conductor 14 has a side opening opposite theisolating rocker 20.

The isolating rocker 20 is furthermore connected to a driveshaft 27 suchthat they rotate together, and the driveshaft 27 is passed out of theintermediate enclosure 19 via a rotating bearing which is expedientlyequipped with sealing means. Rotation of the driveshaft 27 moves theisolating rocker 20 to a disconnected position 28, which is indicated inFIG. 1 and in which the switching pin 13 is withdrawn from the femalecontact 8, so that an isolating gap is formed between the female contact8 and the sliding contact 9.

A grounding switch 29 can be seen in the outdoor bushing 4 which isshown on the left, on the holding cap 21 and opposite the isolatingrocker 20, with the purpose of grounding all of the drive-side contactpieces of the switch disconnectors 7 for one phase once the switchdisconnector 7 has been opened. For this purpose, the grounding switch29 produces a conductive connection between a ground contact 30, whichis at the same potential as the connecting conductor 14, and theenclosure 2, which is at ground potential. A grounder shaft 31, which ispassed out of the intermediate enclosure 19, is provided in order todrive the grounding switch 29. Furthermore, a drive box 32, which isattached to the intermediate enclosure 19, is provided in order toaccommodate drive units. The drive units are designed to produce a drivemovement for the driveshaft 21 and, to some extent, for the groundershaft 31.

The enclosure 2 and thus the entire switch disconnector arrangement areconnected via a supporting frame 33 to a foundation, which is notillustrated in the FIGURE.

The outdoor bushing 4 is also equipped with a current adaptor 34. Aconnecting stub 35 for connection of a voltage transformer, which is notillustrated, can be seen underneath the housing 2.

1. A switch disconnector arrangement for disconnecting air-insulatedelectrical lines of at least one phase, the switch disconnectorarrangement comprising: at least one grounded enclosure filled with aninert gas; a pole element located in said enclosure; and at least threeoutdoor bushings provided for one phase of the electrical lines, saidoutdoor bushings attached to said enclosure in a gas-tight manner, eachof said outdoor bushings including an outdoor connection for connectingthe electrical lines of the one phase, each of said outdoor bushingsincluding a gas-insulated switch disconnector located therein; saidoutdoor connection of each of said outdoor bushings, which are providedfor one phase of the electrical lines, being electrically connectedtogether by said switch disconnector of each one of said outdoorbushings and said pole element.
 2. The switch disconnector arrangementaccording to claim 1, wherein said outdoor bushings, which are providedfor one phase of the electrical lines, are located to form a fan on oneplane.
 3. The switch disconnector arrangement according to claim 1,further comprising: a plurality of posts holding said pole element insaid enclosure; said plurality of posts made of a dielectric material.4. The switch disconnector arrangement according to claim 1, furthercomprising a grounding switch.
 5. The switch disconnector arrangementaccording to claim 4, wherein said grounding switch is located in one ofsaid outdoor bushings.
 6. The switch disconnector arrangement accordingto claim 1, wherein each of said outdoor bushings includes holding meansholding said switch disconnector therein, and said holding means is madeof a dielectric material.
 7. The switch disconnector arrangementaccording to claim 6, wherein said holding means is gas-tight.
 8. Theswitch disconnector arrangement according to claim 6, wherein saidholding means is gas-permeable.
 9. The switch disconnector arrangementaccording to claim 1, wherein: said switch disconnector includes aplurality of contact pieces including ends located opposite one another;and said switch disconnector is linearly movable from a contactposition, which allows a current to flow, into a disconnected position,which provides an electrically isolating gap between said plurality ofcontact pieces.
 10. The switch disconnector arrangement according toclaim 1, wherein: each of said outdoor bushings includes attachmentmeans; said switch disconnector includes a switching pin, a stationaryfemale contact, a sliding contact, and a hollow connecting rod firmlysupporting said sliding contact on said attachment means; and saidsliding contact moveably guides said switching pin for contacting saidfemale contact.
 11. The switch disconnector arrangement according toclaim 10, further comprising: at least one driveshaft mounted in saidattachment means; said driveshaft introducing a drive movement into saidswitch disconnector.
 12. The switch disconnector arrangement accordingto claim 1, further comprising: an isolating rocker for introducing adrive movement into said switch disconnector; said isolating rocker madeof a dielectric material.
 13. The switch disconnector arrangementaccording to claim 1, wherein each of said outdoor bushings includesfield control elements preventing partial discharges in said outdoorbushings.
 14. The switch disconnector arrangement according to claim 1,further comprising a display element for indicating a position of saidswitch disconnector.
 15. The switch disconnect or arrangement accordingto claim 1, wherein at least one of said outdoor bushings includes acurrent transformer.
 16. The switch disconnector arrangement accordingto claim 1, further comprising at least one drive unit supported on oneof said outdoor bushings for producing a drive movement.
 17. The switchdisconnector arrangement according to claim 1, further comprising avoltage transformer.
 18. The switch disconnector arrangement accordingto claim 1, further comprising: at least three outdoor bushings providedfor an additional phase of the electrical lines, said outdoor bushingsattached to said enclosure in a gas-tight manner, each of said outdoorbushings including an outdoor connection for connecting the electricallines of the additional phase, each of said outdoor bushings including agas-insulated switch disconnector located therein.